Cory's Shearwater
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| Cory's Shearwater | ||||||||||||||
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| Calonectris diomedea'' (Scopoli, 1769) |
The Cory's Shearwater (Calonectris diomedea) is a large shearwater in the seabird family Procellariidae.
This species breeds on islands and cliffs in the Mediterranean, with the odd outpost on the Atlantic coast of Iberia. The nest is in a burrow or among rocks, and is visited at night to minimise predation from large gulls. In late summer and autumn, most birds migrate into the Atlantic as far north as the south-western coasts of Great Britain and Ireland. They return to the Mediterranean in February.
This bird flies with long glides, and always with wings bowed and angled slightly back, unlike the stiff, straight-winged flight of the similarly-sized Great Shearwater.
This shearwater is identifiable by its size, at 45-56 cm lin ength and with a 112-126 cm wingspan. It has brownish-grey upperparts, white underparts and yellowish bill. It lacks the brown belly patch, dark shoulder markings and black cap of Great Shearwater.
The endemic Cape Verde Islands race is distinctive. It has an all dark, slim bill, and darker head and upperparts than other forms. The flight has been described as rather more typically shearwater like than other subspecies of Cory’s, with stiffer and more rapid wing beats. It is sometimes given specific status as Cape Verde Shearwater, C. edwardsii ((Oustalet), 1883).
The Mediterranean and Atlantic races are more closely similar in appearance, although the Atlantic race is considerably larger. They are best distinguished by the pattern of the underwing. The Mediterranean race is sometimes regarded as a separate species, Scopoli's Shearwater.
The Cory's Shearwater feeds on fish, molluscs and offal. It readily follows fishing boats, where it indulges in noisy squabbles. This is a gregarious species, which can be seen in large numbers from ships or appropriate headlands. The Bay of Biscay ferries are particularly good for this species. It is silent at sea, but at night the breeding colonies are alive with raucous cackling calls.
This bird was named after the American ornithologist Charles B. Cory.nl:Kuhls pijlstormvogel pl:burzyk żółtodzioby